1. Field of the Invention
The present invention relates to a cable type steering system in which a steering wheel and a steering gear box are connected to each other with flexible operation cables, such as a Bowden cable. More particularly, the present invention relates to a cable type steering system having means or mechanisms for preventing water or other liquids from making contact with the operation cables.
2. Description of the Related Art
Cable type steering system are disclosed in, for example, JP-A-2000-25623, JP-A-10-59197 and JP-A-8-2431.
In this type of cable type steering system, a drive pulley and a driven pulley are accommodated in a drive pulley casing and a driven pulley casing, respectively. Then, ends of inner cables of operation cables are wound around the drive pulley and the driven pulley, and ends of outer tubes of the operation cables are fixed to the drive pulley casing and the driven pulley casing.
Since the driven pulley casing of the cable type steering system is disposed in an engine compartment of a vehicle, muddy water splashed by front wheels tends to adhere to the driven pulley casing. Moreover, since vibrations from the front wheels are transmitted to the driven pulley casing via tie rods, a connecting portion of the driven pulley casing and the outer tubes of the operation cables tends to become loosened. Thus, water penetrating from the loosened connecting portion may adhere to slide portions of the outer tubes and the inner cables of the operation cables. In addition, water penetrating from a joint or a gap in the driven pulley casing may also adhere to the slide portions. Thus, in the event that water adheres to the slide portions of the outer tubes and inner cables of the operation cables, there is caused a problem that water so adhering becomes frozen when the temperature is decreased, thereby interrupting the smooth operation of the cable type steering system, or a problem that rust is generated on the inner cables to thereby deteriorate the durability thereof.
In addition, although the drive pulley housing disposed on a dashboard exists in an environment which makes the penetration of water thereinto more difficult than the penetration of water into the driven pulley housing, the above problems can occur, for example, when a drink is spilt over the drive pulley housing by the driver or passenger in the passenger compartment.